Following on from my lengthy post on the topic of what the heck Web 2.0 actually is, an excellent paper on Web 2.0 [PDF format] has appeared on Pew Internet's website. It draws on Hitwise data about the growth of usage of certain "Web 2.0" sites (such as Wikipedia) compared to the stagnation of "Web 1.0" sites (such as, ahem, Encarta):
They have a number of other comparisons they make which quite nicely characterize Web 2.0 vs Web 1.0:
They also provide some data that indicates that Web 2.0 is being driven by the younger generation - though a post on the Hitwise blog (via which I found this report) has some interesting data which indicates that YouTube's audience has been getting older during 2006:
I imagine this data makes Google feel a bit better about shelling out $1.65bn for YouTube - 35-44 year-olds usually have more spending power than the 18-24's.